[Abnormal expression of chemokine receptor on B cells in patients with SLE]

SLE is a systemic autoimmune disease characterized by overactivation of autoreactive memory B cells. However, little is known about the mechanism of qualitative abnormality of B cells. The subset classification of T cells by expression pattern of master transcription factors and chemokine receptors has been established. The biology of T cells is useful information to assess qualitative abnormality of B cells. Therefore, we focused on the expression of chemokine receptors such as CXCR5 and CXCR3 on B cells in order to define the B cell subset classification in patients with SLE. Our results revealed that pathological B cells, which lose CXCR5 and express CXCR3, might be involved in autoantibody production through the interaction with Tfh cells, and in acquisition of effector function of memory B cells during the pathological process in SLE. In addition, the results revealed that those effector B cells still remained after improvement of disease activity by immunosuppressive therapy, indicating that the quantitative abnormality, which is not improved by current therapy, may underlie in this disease.